Loading ...” To my surprise it looks like 2/3 of the island is not buildable upon. ”
That’s conservative…. I’d say more. The entire south half… the domain of Mauna Loa… is fresh lava of various grades. My eastern area has a thin veneer of jungle only because it gets a lot of water here on the windward side. But there is a reason the Mars Crew isolation habitat was built on the slopes of Mauna Loa.
Mauna Kea slopes on the noth half are older, rich soil and farming areas. Real estate is more expensive up there.